An AAC app is meant to be a permanent, round-the-clock, growing communication device for a child.
As a “voice” for a non-verbal child, it must, therefore reflect the words, concepts and language that are used in a specific child’s life. While it’s important to choose an AAC device whose default vocabulary is robust and promotes effective language use, it is absolutely essential to customize it for a child’s use. For example, the food, the people, the toys and the entertainment in a child’s vocabulary are likely to be highly individualized, and can never be available “out of the box”. The caregiver must add these words, or suitably edit words in the default vocabulary, to reflect these realities.
It’s important that these changes are easy enough to make by any (adult) communication partner of the child — the parent and the teacher included. Special words enter a child’s life from a variety of different environments, and the adult caregivers in each of those environments should feel empowered to add to the child’s vocabulary.
It’s also important that the changes to the vocabulary are done quickly — ideally, without interrupting the flow of a conversation. For example, if a child is going to the cafeteria with a teacher, and the teacher discovers that there’s spaghetti on the lunch menu but no spaghetti in the child’s AAC vocabulary, it’s of very little utility to add this word in after the mealtime is over — it must be added right away.
There is support from recent research for the efficacy of quick addition in improving communication outcomes. Known in the field as “just-in-time customization”,it has been found that if the process of adding a word to a vocabulary can be done in a few seconds, it has a tremendous impact on maintaining the child’s intent to communicate.
While adding a word to a child’s vocabulary, it is extremely important not to disturb the rest of the vocabulary unless there is a very important need. The default vocabulary of an AAC app must ideally provide ‘gaps’ to facilitate the addition of new words. If old words are displaced or removed when new words are added, it can result in chaos — the child can no longer find words they may have regularly used, or their motor patterns are disrupted, causing a drop in fluency. If major changes are to be made to vocabulary, it is suggested to do those changes before introducing the AAC device to the child.